How Did The Royal Oak Sink?
In the early days of the war the German High Command were determined to strike at the heart of the British defences and gain the upper hand in the propaganda campaign.
Commodore Donitz dreamed of and plotted a raid on the base at Scapa Flow in Orkney, Scotland and, after intense study of photographs taken by a plane flying high over the base, chose the tide swept channel through Kirk Sound as a possible, if dangerous, route into the anchorage.
During World War 2, Orkney acted as a base for training and repairs for many of the aircraft from aircraft carriers, although it took some time to make the harbor secure for use as a base, in both wars. Orkney was so important to the war effort that there were up to 40,000 men stationed there at the peak of World War 2. To put that in perspective, in 2019, the population was only 22,000.
The four eastern entrances into Scapa Flow had been blocked by sunken ships in the First World War but the rusting hulks had been gradually torn apart by the fierce tidal streams which rushed through these narrow channels at up to ten knots.
The night of Friday 13th October, 1939 was chosen for the daring raid.
An extremely high tide and no moon made it perfect for the dash through the defences. Slack water was due thirty minutes before high tide at 11.30pm making it ideal for the risky trip through Kirk Sound. A commander of equal daring was required for the mission. Donitz chose Lieutenant Gunther Prien, a thirty year old ace with three kills already to his credit in the early days of the war.
On October 8th, Prien and his crew cast off from the dockside at Kiel and headed into the North Sea. It was probably just as well that the crew did not know their target as they left. Two similar attempts to penetrate Scapa Flow in the First World War had ended in disaster with the loss of one U-boat and the capture of the other.
However, as U-47 (pictured above) settled to the bottom of the North Sea to await nightfall before proceeding northwards on the surface, Prien quietly told his men that they were to breach the defences at Scapa Flow and attempt to sink any ships they found there. The men were left to their own thoughts as they headed north that evening.
Meanwhile, the British fleet were in action attempting to chase down the German battleship Gneisenau off Norway although the slower Royal Oak was left well behind in the pursuit. After a fruitless two day search, the fleet was ordered to return to base but, in a fateful decision, they were ordered to disperse to a number of alternate bases rather than return to Scapa.
However, Royal Oak did return to her usual berth, dropping anchor in the north east corner of the Flow at 07.05am of the 11th . The seaplane carrier Pegasus anchored about a mile north, closer to the shore.
On the evening of the 13th, U-47 surfaced in the Pentland Firth and raced north the last few miles before turning west into Kirk Sound.
The night was unexpectedly bright with a magnificent display of the Aurora Borealis casting a glow over the calm waters.
Prien was forced to crash dive his vessel when an unidentified surface ship came towards them but it passed without incident. However, by then, the dive had delayed them by thirty minutes meaning that they would miss slack water in Kirk Sound. This did not deter Prien.
Ahead of him lay the short, treacherous trip between the blockships. The photographs used to plan the mission were excellent but the scene ahead was still menacing.
Three blockships straddled the sound.
The 2890 ton steamship Minieh, sunk in 1915, lay in the middle of the channel. North of her, the 3543 ton steamship Seriano, sunk only months earlier, stretched to within two hundred feet of the northern shore.
To the south, the 1327 ton steamship Thames was the last obstacle in this metallic barrier.
Ironically, another ship, the 3859 ton steamship Lake Neuchatel was due to arrive in Orkney that same weekend and was to be sunk in Kirk Sound to block the four hundred feet gap between the Thames and the Minieh which had been created when the Aorangi was moved during a salvage attempt in 1920.
Already the fierce tide was streaming through the gaps between the blockships. The chosen path for U-47, north between the Seriano and the shore, looked frighteningly narrow in the ghostly light of the Aurora Borealis. It was further narrowed by a heavy hawser reaching from the sunken ship to the shore.
Prien steered his ship towards the narrow twenty four feet deep channel (U-47 drew only fifteen and a half feet). Disaster nearly struck when the bow of the U-boat went aground and the stern was pushed onto the protruding cable from the Seriano but Prien calmly blew his forward ballast tanks and his ship pulled free and was catapulted through the gap.
In response to the attack, First Lord of the Admiralty Winston Churchill would order the construction of several permanent barriers to prevent any further attacks.
Huge concrete blocks would be assembled across the channels, replacing the unreliable sunken blockships with more permanent and impenetrable barriers. Work would begin in May 1940 but would not be completed until September 1944. The barriers were officially opened on 12 May 1945, four days after the end of World War II in Europe.
‘We are in,” announced Prien over the ship’s intercom. It was 00.27am on the 14th.
Inside Scapa Flow, despite the dispersal of the fleet, fifty one vessels lay at anchor. Among them there were only eighteen fighting ships with the main concentration in the heart of the anchorage between the islands of Flotta and Fara.
Aboard the ships the crews had turned in for the night content in the knowledge that they were in one of the Royal Navy’s safest anchorages.
Prien could not believe his eyes when he entered Scapa Flow.
As he strained through the now fast reducing visibility he couldn’t see any ships at all. He first headed west towards Flotta but then, fatefully, turned back north east towards the Royal Oak. At this stage he could not have known that she was anchored in this corner of Scapa. Soon the shapes of what Prien thought were two capital ships appeared through the night.
There were indeed two ships anchored in that corner of the base but it seems unlikely that Prien could see Pegasus which was lying a mile north beyond the Royal Oak. He mistakenly identified the second shape as the battleship Repulse. He prepared his ship for action. He fired three torpedoes from his forward tubes from a range of 3200 yards and a further single shot from his stern tube before retreating south to await the results.
At 01.04am a single explosion near the bow of the Royal Oak signalled his initial success. However, aboard the battleship, Captain William Ben and his crew did not stop for a second to consider an enemy attack.
Immediately it was assumed that an internal explosion had caused the problem and, while the fire crew assembled to extinguish the blaze, most of the crew simply turned over in their bunks and went back to sleep. The crew were to be rudely awakened shortly after when Prien fired another three torpedoes from 3000 yards on his second run.
This time all three torpedoes smashed into the starboard side of the Royal Oak and exploded, sending huge plumes of spray high into the air along the side of the ship.
As the noise of the explosions died a deafening rumble echoed through the ship as both anchor chains snapped and ran out, plunging in a boiling rage into the sea beneath the bows of the stricken ship.
Many men were killed instantly in the explosions.
The huge ship rolled heavily as the torpedoes hit but she quickly settled back with an immediate twenty degree list.
The devastation below was increased when one of the cordite magazines exploded sending sheets of flame ripping through the under deck compartments killing many more of the crew who were, by now, scrambling around in the darkness trying to get to the deck before the ship turned turtle and sank with 835 souls aboard.
U-47 was able to pass back through Kirk Sound and return to Wilhelmshaven, where the ship was met by Grand Admiral Raeder and Admiral Dönitz. Thereafter, KptLt. Prien and his crew were flown to Berlin for an audience with the Führer.
In addition to the human loss, the loss of the Royal Oak was a public relations nightmare for the Admiralty, and a bonanza for the Nazis, and the predictable recriminations and propaganda ensued.
How Did The Royal Oak Sink? Written by Harry Gillespie
Harry Gillespie is a military historian who resides with his wife in the United Kingdom.
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How Did The Royal Oak Sink?